Fire-check.



W. F. SOMES.

FIRE CHECK.

' APPLICATION men OCT. 11, 1917.

Lfi4hfiw Patented Feb. 18, 1919.

worroe s.

To all whom it may concern:

i T OFFICE.

WALTER IF. SOMES, 0F BOSTON, MASSACHUSETTS, ASSIGNOR 'I'O WILLIAM B.MERRILL, 0F NEWTON, MASSACHUSETTS;

FIRE-CHECK.

Specification of Letters Patent.

Patented Feb. 18, 1919.

Application filed October 1'7, 1917. Serial No. 197,067.

Be it known that I, WALTER F. SoMns, a citizen of the United States, andresident of Boston, in the county of Suffolk and State of Massachusetts,have invented new and useful Improvements in Fire-Checks, of which thefollowing is a specification.

This invention relates to fire checks to be used in conjunction with thepackings of the piston rods of gas engines. More particularly theinvention relates to a segmental ring fire check which shall beadjustable to take up wear.

Heretofore fire checks have usually been made in the form of an integralring which closely surrounds the piston rod at the side of the pistonrod packings toward the engine cylinder. When the inner surface of suchrings Wears away, or when the rod itself wears, or both, so that thejoint between the fire check and the rod is no longer sufficientlytight, the fire check ring is discarded and a new one applied. With thesegmental ring of the present invention the fire check may be adjustedin the manner hereinafter described to insure a proper fit when theparts become worn.

The principal objects of the present invention are to provide asegmental fire check of such construction as to form a tight barrieragainst the passage of combustion gases, to provide for adjustment so asto prolong the useful life of a fire check, to prevent the pressurewithin the cylinder from forcing the fire check ring segments outwardlyfrom the piston rod, to utilize the pressure within the cylinders tohold the ring segments against each other and the piston rod, and

to prevent or lessen localized wear on the checks and surrounding thepiston rod A, is

provided with suitable annular grooves and packing-rings, as usual andnot shown, and

may be lubricated in any desired manner. The interior of the cylinder isto the left as shown in Fig. 2, the fire checks being subjected topressure of hot gases acting in the direction of arrowa. Each segmentalfire check ring 1,2, 3, 4, is held in an internal annular recess 12 inthe part of easing C nearest the cylinder.

The segments 1, 2, 3, 4, whatever their number and form, are arranged tofit together at their complemental abutting ends so as to besubstantially gas-tight under the usual conditions of lubrication, thethickness of the ring and the width of the casing recess being such asalso to make a tlght joint wlthout employing two or more staggeredsegmental rings in one annular ring-space.

Preferably the complemental end surfaces of the segments in mutualcontact are flat, but fitting convex and concave, or other surfaces maybe employed without departing from my invention.

While any suitable number of segments may be employed, the particularembodiment of the invention illustrated in the figures is made up offour like segments, 1, 2,3 and 4, each segment having substantially aquadrant bearing surface and extending through somewhat more than 90 soas to fit together in overlapping relationship. For instance, eachsegment is provided with a recess at one end and a projection 1 at theother end fitting into the recess of the next adjacent segment, thesurfaces 5 of the recesses lying preferably in a tangential direction.or substantially at right angles to axial planes V-V and HH respectivelynear the ends 1? of the segments. The abutting end-surfaces 6 of theprojections and recesses, which limit the minimum diameter of the ring,are disposed crosswise of the ring, preferably at right angles to thebottoms 5 of the recesses and parallel with the respective planes VV andHH. The surfaces 5, while preferably tangential to a diameter near thejoints, may not be so positioned so long as diametrically oppositejoints 180 apart on the ring, whatever the number of segments, compriselines of juncture at .5 which are parallel, so that the ring may beopened and closed on a diameter by sliding these surfaces one on theother. An even number of segments is for this reason preferred.

" The ends 1 of the segments projecting the axial planes V-V and'H-H, asshown in Fig. 1, so that the extreme ends of the projections are ofsubstantiallyv a constant cross-section and of the same radial thicknessthroughout a considerable distance, the

extreme ends thus being of the same thick-- ness at points disposed oneach side of an axial plane a distance equal to the distance between theends of the projections and the axial plane and substantially of thesame 7 thickness throughout a distance at the end out alteringthe fit atsurfaces 5, 6. To avoid employing any elaborate jigs or tools toaccurately machine, mill or grind the ends 1 to take up wear, 'I preferto provide accurately placed holes 13 in the same relative positions ineach segment, in a part of the segment housed in grooves 12, so that astack of the segments can be strung on a rod and clamped or chuckedtogether for milling or grinding off the required amount of the A bandspring 7 is provided to hold the segments together in the form of aring. The spring is secured to one segment by means of a screw or stud8, and engages the raised portions 9 disposedon the respectivesegmentsin the regions'of the joints between them, the spring pressingagainst each segment only at the region of its recess. A filler or strip10 is preferably mounted on the segment disposed between the ends of theband spring so as to equalize the outer diameter of the assembledstructure.

Slots 11 are provided on that faceof each fire check which is disposedtoward the 7 cylinder so as to permit free communication between theopen space in the annular recesses 12 and the interior of the cylinderfor thepassage of fiuid-pressure from the inner side of the ring facingthe pressure to the outer periphery of the ring. The outer peripheralsurface of the ring 1, 2, 3, 4 being of greater area than the innersurface, leakage about the rod A tending to force the segments outwardlyis overbalanced, a pressure component being exerted toward the rod tohold the segments to a bearing against each other and on the rod A.

y In Fig. 2 I have shown two fire checks in series, and it will beunderstood that any suitable number of my improved checks may beemployed in'series or that a single check may be employed alone. While asingle Oopies'of this patent may be obtained for check forms aneffective close barrier against the passage of the burning gases, Iprefer to employ at least two checks in series.

In order to prevent unequal wear of the rod A or the ring segments dueto gravity ofthe ring, a counterbalance spring 15 may be provided in thelowest part of each annular recess 12, preferably being attached at oneend to casing C as by a driven headed pin 16 in a hole in the casing.Spring 15 is strong enough td sustain the weight of the ring 1, 2, 3, 4.

The filler 10 and the band-spring 7 form a periphery for the assembledring against which the spring 15 is efiective in any rotative positionof the ring, which has freedom to rotate about the piston-rod.

What I claim is:

1. 'A fire-check ring having a plurality of interfitting like segments,each segment having an end fitting against a complemental part of anadjacent segment, said end having one surface adapted to be cut away toadjust the diameter of the ring, the segment. near said end being ofsubstantially constant cross-section, whereby the ring may be readilyaltered to compensate for wear without changing the fitting relation ofits other complemental surfaces.

2. A fire-check device comprising a casing, a segmental gas-check ringtherein, a p eripheral band-spring attached to one segment to hold thering assembled, and a spacer between the ends of the spring to maintainthe peripheral surface of the ring, in combination with a counterbalancespring in said casing adapted to act on the peripheral surfaces of saidband-spring and spacer.

3. A segment for a segmental fire-check ring comprising ends ofcomplemental form adapting like segments to be fitted together, one ofsaid ends being adapted to be altered by a cutting operation, saidsegment being provided with an opening related to said alterable end,whereby a series of such segments may be strung on a rod forsimultaneous and similar alteration of each of the series of segments bya machining opera tion.

4:. A fire-check ring made up of segments whose complemental ends abutand fit and thereby resist decrease in the size of the assembled ring,the joints between segments being sufficiently tight for use as afirecheck, in combination with a peripheral band spring surrounding thesegments and bearing on all of the segments, whereby to hold the ringassembled with the abutting ends of the segments in contact.

' Signed by me at Boston, Massachusetts, this first day of October,1917.

WALTER F. SOMES.

five cents each, by addressing the Commissioner of Patents, W ng n, 3,6.

